Electrochemical corrosion mechanisms of nickel-aluminium bronze with different nickel contents using the rotating disc electrode

The open circuit potential, cathodic and anodic polarisation characteristics of nickel-aluminium bronze (NAB) with different nickel contents in 3.5 wt.% NaCl solution were investigated under well-defined hydrodynamic conditions. The results showed that irreversible cathodic oxygen reduction reaction was under kinetic control, whereas the reversible anodic copper dissolution reaction was under mixed transport-kinetic control. The increase in Ni content decreased the total amounts of alpha phase and beta' phase in the microstructures of NAB alloys, resulting in the decrease in both cathodic kinetic current and anodic current, and thus improved the corrosion resistance of NAB alloys under flowing conditions.